WZ Doradus

WZ Doradus
Location of WZ Doradus on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Dorado
Right ascension 05h 07m 34.02686s[1]
Declination −63° 23′ 58.8474″[1]
Apparent magnitude (V) 5.20 - 5.32[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type M3 III[4]
U−B color index +1.85[5]
B−V color index +1.65[5]
Variable type SRb[2]
Astrometry
Radial velocity (Rv)19.3±2.8[6] km/s
Proper motion (μ) RA: +13.210 mas/yr[1]
Dec.: −44.813 mas/yr[1]
Parallax (π)5.6282 ± 0.1116 mas[1]
Distance580 ± 10 ly
(178 ± 4 pc)
Absolute magnitude (MV)−1.00[7]
Details
Mass1.4[8] M☉
Radius88.3+6.6
−10.0[9] R☉
Luminosity1,248±47[9] L☉
Surface gravity (log g)0.50[10] cgs
Temperature3,603±125[10] K
Other designations
21 G. Doradus[11], WZ Dor, CD−63°188, CPD−63°420, FK5 2389, GC 6314, HD 33684, HIP 23840, HR 1695, SAO 249198, TIC 55298910[12]
Database references
SIMBADdata

WZ Doradus (HD 33684; HR 1695; 21 G. Doradus) is a solitary red-hued variable star[13] located in the southern constellation Dorado. It has an average apparent magnitude of 5.21,[14] making it faintly visible to the naked eye under ideal conditions. Gaia DR3 parallax measurements imply a distance of 580 light-years[1] and it is currently receding with a heliocentric radial velocity of 19.3 km/s.[6] At its current distance, WZ Doradus is diminished by two-tenths of a magnitude due to interstellar extinction and it has an absolute magnitude of −1.00.[7]

HD 33684 was first observed to vary in brightness by astronomer P. M. Corben in 1971.[15] It was said to have an amplitude of 0.18 magnitudes. A year later, HD 33684 was given the variable star designation WZ Doradus.[16] It was again observed in 1973 by Olin J. Eggen and he noticed that it varied within 40 days.[17] A 1998 survey found no strong emissions indicating dust around the star.[18] Another survey also found no technetium in its spectrum.[19] WZ Doradus is a semiregular variable of subtype SRb that varies between 5.2 and 5.32 within an average period of 40 days.[2] Tabur et al. (2009) found two periods for the star after it was widely believed to only have one period.[20]

WZ Doradus variability periods[20]
Amplitude (mag) Period (days)
0.042 26.0
0.026 44.6
A light curve for WZ Doradus, plotted from data published by Tabur et al.[20]

WZ Doradus has a stellar classification of M3 III,[4] indicating that it is an evolved red giant. It is currently on the asymptotic giant branch,[3] generating energy via the fusion of hydrogen and helium shells around an inert carbon core. As a result of its evolved state, it has expanded to 88.3 times the radius of the Sun[9] and it now radiates 1,248 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperature of 3,603 K.[10]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Eggen1992 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference kervella2019 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference McDonald2017 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Corben1971 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Kurkakin1972 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Eggen1973 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Sloan1998 was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Lebzelter1999 was invoked but never defined (see the help page).
  20. ^ a b c Cite error: The named reference Tabur2009 was invoked but never defined (see the help page).